DENPASAR, Indonesia (Reuters) - A United States attorney advised an American teen and her boyfriend not to make any statements about the death of the woman's mother, whose body was found in a suitcase on the resort island of Bali, until he arrives, an Indonesian lawyer said on Thursday.

The couple's police-appointed lawyer Haposan Sihombing said he spoke with Mr Elkin on Wednesday and the American lawyer had not yet confirmed he would be travelling to Indonesia.

Mr Sihombing said Ms Mack had refused to talk to him. "I again tried to explain to Heather that under Indonesian law, if Michael Elkin does come, he could not act as her lawyer," Mr Sihombing told Reuters. "I told her this is being uncooperative. You must not be secretive and be open about this."

Asked if Ms Mack was sure Mr Elkin would come, Mr Sihombing said: "She is sure he will come and has said that Elkin advised her to give no statement until he arrives."

US lawyer Michael Elkin had yet to travel to Indonesia and meet Ms Heather Mack, 19, and Mr Tommy Schaefer, 21, who were arrested last week as suspects in the death in the murder of Ms Mack's mother. They have not been charged.

Ms Sheila von Wiese-Mack's battered body was found in the bloodied suitcase in a taxi outside the luxury St Regis hotel.

Ms Mack and Mr Schaefer have been placed on suicide watch and the two have not been allowed to see each other, despite repeated requests from Ms Mack.

Police last week provided CCTV footage showing the couple speaking to a taxi driver after dropping the suitcase along with other luggage outside the hotel.

Police said the two left, apparently to check out of the hotel, and never returned. The case was lifted into the back of a taxi.

The two were arrested at a nearby budget hotel.

An official at the hospital that conducted the autopsy said Ms von Wiese-Mack had been repeatedly hit on the face and head with a blunt object.

The body was flown back to the United States on Tuesday accompanied by an officer with the US Federal Bureau of Investigation, which is assisting in the investigation.